1. Field Of The Invention
The present invention relates to wireless communications equipment. More particularly, though not exclusively,.the present invention relates to an integrated matched antenna structure and method for using the same.
2. Problems In The Art
Many devices utilizing wireless communications use an antenna having a high impedance which requires the use of a matching circuit when connected to a transmitter or receiver to provide the maximum energy transfer to the antenna. In a typical prior art device, manufacturers add a matching circuit comprised of a number of discrete components soldered to a circuit board. When using a matching circuit, it is advantageous to reduce the size and cost of the matching circuit.
Typical prior art matching circuits utilize small size discrete components using surface mount methods to mount the discrete components to a circuit board. One disadvantage of using this technique comes from the necessity to either machine or hand place these components onto the circuit board. This requires additional assembly operations and an increased parts count thus increasing the size and cost of production. The small discrete components also have a lower power handling capability which limits the amount of power that can be dissipated in the circuit. The use of externally placed components also limits the packaging methods that can be used such as injection molding.
A typical prior art design of matching circuits to be used with an antenna to match a high or low impedance to a 50 ohm feed point have generally used discrete inductors and capacitors manufactured by component manufacturers and then placed into the circuit by conventional assembly techniques as noted above.
A technique is known in the prior art wherein microstrip transmission lines are used to form inductive or capacitive elements. However, these techniques use the inherent lumped constants associated with a transmission line and require lines of various widths and lengths to obtain the corresponding desired circuit element. The resulting transmission lines are fairly narrow in bandwidth and require extensive area on a printed circuit board.
3. Features Of The Invention
A general feature of the present invention is the provision of an apparatus and method for receiving or transmitting signals which overcomes problems found in the prior art.
A further feature of the present invention is a provision of an apparatus and method for receiving or transmitting signals which includes a matching circuit which is formed on a printed circuit board using printed circuit techniques.
A further feature of the present invention is the provision of an apparatus and method for receiving or transmitting signals which uses a matching circuit formed on a substrate eliminating the need for discrete elements.
Further features, objects and advantages of the present invention include:
An apparatus and method for receiving or transmitting signals which includes a matching circuit having an inductive and a capacitive element formed on a substrate.
An apparatus and method for receiving or transmitting signals which includes a substrate having a matching circuit and an antenna formed on the substrate.
An apparatus and method for receiving or transmitting signals which includes a matching circuit formed on a multilayer substrate which includes no discrete components.
An apparatus and method for receiving or transmitting signals which includes a matching circuit which has a higher efficiency and experiences less losses than circuits of the prior art.
An apparatus and method for receiving or transmitting signals which includes a matching circuit which is cheaper, easier to manufacturer, more reliable, and performs better than matching circuits of the prior art.
These as well as other objects, features and advantages of the present invention will become apparent from the following specification and claims.
The present invention relates to a method and apparatus for matching the impedance an antenna to that of an electronic circuit. A substrate is provided on which an inductor and capacitor are formed on the substrate using printed circuit techniques. An antenna is electrically connected to the matching circuit. The antenna may optionally be a conventional antenna or may be formed on the substrate.